1. Field of the Invention
This invention relates to reinforcement and anchor assemblies for use in masonry backup walls and, in particular, cavity wall constructs with backup and veneer walls that require superior anchoring properties. The backup wall reinforcement is a hybrid anchoring system which includes a reinforcement with an integrated anchor for connection to an interlocking wire formative veneer tie which, upon installation, provides a 3-axis restraint system, limiting exterior wall movement and displacement.
2. Description of the Prior Art
Masonry, the building of structures from individual units laid in and bound together by mortar, is commonly used for the construction of buildings. Such widespread use is the result of the high durability, compressive strength, thermal mass and heat resistance of the masonry building materials. Because masonry construction requires extensive manual labor and individual building materials, the quality of the masonry construction is directly dependent on the type of materials and devices used and the workmanship of the mason.
In recent years, attention has been paid to wall reinforcement for areas that are subjected to external forces such as high winds and seismic activity. To address a difficulty with masonry construction, weakness of the horizontal mortar or bed joints that bond the masonry units together, well-known devices such as ladder and truss reinforcements are used to augment the tensile strength of the horizontal mortar joints. Any weakness in the bed joints resulting from low tensile strength mortar, has been generally addressed by providing mortar joint reinforcement for structural stability. The ladder and truss reinforcements have been historically used to reduce cracking that arises from thermal stresses, to increase lateral flexural strength, and to enhance the elasticity and performance of masonry walls under various stresses.
Further seismic protection is achieved through the use of a continuous wire in the veneer masonry walls. In the past, there have been investigations relating to the effects of various forces, particularly lateral forces, upon brick veneer construction having wire formative anchors embedded in the mortar joint of anchored veneer walls. The seismic aspect of these investigations is referenced in the prior patents of R. P. Hohmann, Sr., namely, U.S. Pat. Nos. 4,875,319 and 5,408,798. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces has resulted in the incorporation of a requirement for continuous wire reinforcement in the Uniform Building Code provisions.
The inventors' patents and their assignee's product line include masonry accessories, namely, ladder and truss reinforcements, wall anchors, veneer ties, masonry flashing and related items for cavity walls. These products, which are sold under the trademarks of Lox All, DW-10X, X-seal, and FlexFlash, are manufactured by Hohmann & Barnard, Inc., Hauppauge, N.Y. 11788 (“H&B”), a unit of MiTek Industries, Inc., a Berkshire Hathaway subsidiary. The products have become widely accepted in the construction industry and the inventors have gained particular insight into the technological needs of the marketplace.
Recently, there have been significant shifts in public sector building specifications which have resulted in architects and architectural engineers requiring larger and larger cavities in the exterior cavity walls of public buildings. These requirements are imposed without corresponding decreases in wind shear and seismic resistance levels or increases in mortar bed joint height. Thus, the wall anchors needed are restricted to occupying the same ⅜ inch bed joint height in the inner and outer wythes. Thus, the veneer facing material is tied down over a span of two or more times that which had previously been experienced. Exemplary of the public sector building specification is that of the Energy Code Requirement, Boston, Mass. (See Chapter 13 of 780 CMR, Seventh Edition). This Code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities.
Numerous improvements to masonry wall reinforcement have been made by H&B. In 1976, Hala and Schwalberg of H&B, received U.S. Pat. No. 3,964,226 for an adjustable wall-tie reinforcing system which joined reinforcements in inner and outer wythes with an attached eye and pintle structure. During the period when the Uniform Building Code developed joint reinforcement specifications, Hohmann et al., received U.S. Pat. No. 5,454,200 issued Oct. 3, 1995 and U.S. Pat. No. 6,279,283 issued Aug. 28, 2001. Examples of additional H&B inventions which resolve complex issues relating to cavity wall construction include U.S. Pat. Nos. 6,279,283; 6,668,505; 6,789,365; 6,851,239; and 7,325,366. These patents provide veneer anchoring systems for masonry walls which include reinforcement for cavity walls and describe anchors that have received widespread usage in the industry. However, none of these devices offers a hybrid backup wall reinforcement and anchor that when combined with the disclosed wire formative veneer tie provides reinforcement and 3-axis displacement protection.
Basic ladder and truss reinforcements are well known in the art. Exemplary of such basic reinforcements are in a patent to Stephen Priest, Jr., U.S. Pat. No. 903,000 issued Nov. 3, 1908, entitled “Wall Tie,” which provides a reinforcing ladder device constructed of twisted wires with one side of the ladder device embedded in the outer wythe and the other, in the inner wythe. Similarly, H. Spaight, U.S. Pat. No. 2,300,181 issued Oct. 27, 1942, entitled “Means for Constructing Buildings,” teaches a truss shaped reinforcement device for embedment in either one wythe or in cavity walls in both withes. More recently, W. Smith in U.S. Pat. No. 3,183,628 issued May 18, 1965, entitled “Masonry Wall Reinforcing Means,” describes an improvement of the Spaight invention by teaching truss and ladder reinforcements having grooves or bosses on the parallel side wires to increase the mortar bonding therewith. The placement of one of the aforementioned devices in the horizontal mortar joints enhances the tensile strength of the horizontal joints.
The present invention employs a novel hybrid device that combines an inner wythe or backup wall with a wall anchor that provides a 3-axis restraint system, which measurably improves the stability of the overall cavity wall structure. The backup wall reinforcement anchoring system includes an integrated anchor that ensures an unbroken connection between these two essential components and, by integrating the two elements reduces the number of components at the job site. The integrated anchor is constructed in a manner to tightly receive a veneer tie and limit movement of the tie within the anchor. The connection of the anchor and veneer tie is accomplished without tools by manually inserting a veneer tie through the anchor.
Limiting veneer tie movement protects against movement and shifting of the exterior wall, which is a cause of structural damage. Further seismic protection is provided through the attachment of a reinforcement wire to the veneer tie and set within the exterior wall. The hybrid reinforcement and anchor assembly reduces the number of bits and pieces brought to the job site while manual insertion interengagement simplifies installation.
In preparing for this application the below-mentioned patents have become known to the inventors hereof. The following patents, not previously discussed, are believed to be relevant:
PatentInventorIssue Date3,377,764StorchApr. 16, 19684,227,359SchlenkerOct. 14, 19804,819,401Whitney, Jr.Apr. 11, 19894,869,038CataniSep. 26, 19895,392,581Hatzinikolas et al.Feb. 28, 19955,490,366Burns et al.Feb. 13, 19966,351,922Burns et al.Mar. 5, 20026,735,915Johnson, IIIMay 18, 20047,152,382Johnson, IIIDec. 26, 2006
U.S. Pat. No. 3,377,764—D. Storch—Issued Apr. 16, 1968 Discloses a bent wire, tie-type anchor for embedment in a facing exterior wythe engaging with a loop attached to a straight wire run in a backup interior wythe.
U.S. Pat. No. 4,227,359—Schlenker—Issued Oct. 14, 1980 Discloses a preassembled masonry reinforcement for cavity walls with corrugated metal wall ties pivotally and slidably connected with the reinforcement.
U.S. Pat. No. 4,819,401—Whitney, Jr.—Issued Apr. 11, 1989 Discloses a wire anchor for metal stud/brick veneer wall construction. The wire anchor has a U-shaped portion which spans the cavity, a transverse offset portion that engages the stud and a pair of attachment portions that snap into position on the stud.
U.S. Pat. No. 4,869,038—M. J. Catani—Issued Sep. 26, 1989 Discloses a veneer wall anchor system having in the interior wythe a truss-type anchor, similar to Hala et al. '226, supra, but with horizontal sheetmetal extensions. The extensions are interlocked with bent wire pintle-type wall ties that are embedded within the exterior wythe.
U.S. Pat. No. 5,392,581—Hatzinikolas et al.—Issued Feb. 28, 1995 Discloses a cavity-wall anchor having a conventional tie wire for embedment in the brick veneer and an L-shaped sheetmetal bracket for mounting vertically between side-by-side blocks and horizontally atop a course of blocks. The bracket has an opening which is vertically disposed and protrudes into the cavity. The opening provides for a vertically adjustable anchor.
U.S. Pat. Nos. 5,490,366 and 6,351,922—Burns et al.—Issued Feb. 13, 1996 and Mar. 5, 2002, respectively Discloses an adjustable wall tie for cavity walls with a tension anchor connected with an adjustable double-end hook or a J-shaped single-ended hook.
U.S. Pat. Nos. 6,735,915 and 7,152,381—Johnson, III—Issued May 18, 2004 and Dec. 26, 2006, respectively Discloses a masonry anchoring system for connecting two spaced apart masonry walls. The anchor includes a ladder or truss type support for positioning on top of a mortar joint and a bracket that lies in the space between the two walls. The bracket is designed to receive a connecting member to connect the two walls.
Accordingly, while several distinct devices were developed to provide a connection between the backup and exterior walls, the current state of the art does not fulfill the need for an economical hybrid anchor and reinforcement assembly that provides a 3-axis restraint system utilizing a wire formative veneer tie. As described hereinbelow, the present invention provides a manually assembled, integrated backup wall and anchor assembly with a veneer tie connector that upon installation limits movement in x-, y- and z-axes, thereby simplifying installation and providing a useful and novel solution to the aforementioned difficulties.